Ladder.



PATENTED OUT. 22; 1907.

ER LB ID TD .A L .L 1 h 9 6 00 0 N APPLICATION FILED JULYB. 1906.

wvmto'c: fihn Wiley,

PATENT I FFIGE.

JOHN S. TILLEY, OF WATERVLIET, NEW YORK.

LADDER.

Specification of Letters Patent.

Patented Oct. 22, 1907'.

Application filed July 6, 1906- Serial No. 324,923.

To all whom it may concern:

Be it known that I, JOHN S. TrLLnY, a citizen of the United States, residing at \Vatervliet, in the county of Albany and State of New York, have invented certain new and useful Improvements in Ladders, of which the following is a specification, reference being had therein to the accompanying drawing.

This invention relates to an improvement in ladders and more particularly to an improvement in step ladders although its useful application is not so limited.

The invention resides primarily in the ilnproved form of brace, tie or knee designed for the. connecting and sirengthening of joints between the steps and the sides of the adder or between other jointed members.

The object of the invention is that of providing an improved form of brace, tie or knee which can be inserted and secured in a cut or groove formed in. the jointed members and there secured against displacement.

A further object of the invention is to provide an inexpensive, durable and easily applied knee, tie or brace which will well serve the purposes for which it is intend ed.

A further object is the provision of a knee, tie or brace which can be formed of a metal plate cut to shape and which can be so positioned on the ladder as not to interfere with the feet or hands of the user of the ladder and at the same time which will providea very eflici ent brace and tie for the joint.

With the above object in view, I have shown in the accompanying-drawings an embodiment of the invention, although it is to be understood that the construction shown may be modified and changed without departing from the invention.

Figure 1 illustrates a step ladder in perspective showing the knee or brace applied. Fig. 2 is a side view of a portion of the ladder. Fig. 3 I s a longitudinal section taken through the joint showing the knee applied, and Figs. 4 and 5 are modified forms.

A designates the side, I] the step of any conventional form of step ladder. As is well known, the weakness of a step ladder resides in the joint between the steps and the side bar and many efforts have been made to provide means or structures which would cure this weak-.

ening at the joints. In the form illustrated, I cut or otherwise produce a longitudinal groove C in the side of the ladder opposite the end of the step, extending the same conveniently through the entire thickness of the material constituting the side. This groove is extended above and below the plane of the step joint. In the end of the step, I also form a groove D registering and in alinement with the groove formed in the side. These grooves may be properly termed saw grooves, they being relatively narrow.

E designates a metallic brace, tie or knee. This is conveniently formed of sheet metal cut to shape and of a general triangular outline. The plate or brace may be conveniently provided with a series of holes a arranged above and below the plane of the step and also in the angular projection at the end located in the step. In locating the perforations or holes 0 I conveniently place them so that they will occupy a position substantially central of the thickness of the wood of the sides and step, when the knee is in position.

In assembling the parts the knee plate is conveniently but not necessarily inserted from the outside of the side of the ladder and by suitable nails passing through the perforations a and through the ladder sides, is secured in place the inner end or part of the knee plate, which is positioned in the groove of the step, is fastened to the step by a nail or other device passing through the perforation and through the material of the step. In the particular arrangement and construction, it will be observed that the knee plate extends above and below the plane of the step and thus forms in eiiect a T, resisting the twisting or turning tendency. As is usual in such constructions, the step part is mortised into the side to form the joint and when the knee plate is positioned and secured it serves as a reinforce maintaining the rigidity of the joint and preventing the twisting of the step relative to the joint.

InFig. 4, I have shown a slightly modified form, the plate in itself being substantially triangular differing in that respect from the construction shown in Fig. 1 wherein the edge of the plate is slightly cut away so as to prevent the plate from forming an obstruction on the upper face of the ladder step at the corner. In the form shown in Fig. 4 the triangular form serves the purpose of tying and bracing the parts as the construction shown in Fig. 3 and in some instances may be used. The plate is designated at H and in its application the upper edge is horizontal terminating on a plane approximately that of the step. In this form the saw groove is shown as extending only part way into the side and step as at h h and the plate after being inserted in the groove is there secured by nails or other devices, there being two fasteners in the vertical. part of the plate one above the other as shown.

Manifestly other forms of knees can be made, as for instance in Fig. 5 I have shown a doub e thickness plate or a plate folded on itself to constitute a double thickness knee, in which instance the two sides K are of the same shape and are pressed tightly together.

i In practice, it is found that two holes 0 below the plane of the step are desirable so that the knee plate can be secured by three fasteners at the side and one or more can be employed through the inner projection in the step.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is 1. In a ladder, the combination with a side and step part havingjointed connection, of a metallic knee plate in serted in the side and projecting into the step part, the said plate extending above and below the plane of the step, and means for securing the plate in position.

2. In a ladder, the combination with a side and step part, of a substantially triangular metallic knee plate inserted in the side and extending above and below the step having; its inner end inserted in the step, and means for securing the knee in position.

3. The combination with tvvo members jointed together, of a metallic knee or tie inserted in grooves formed in the members, said knee extending into and beyond the angle of the joint and above the joint and means for securing the knee in the grooves.

4. In a ladder, the combination with a side and step' part, of a metallic knee plate inserted in the side and pro- 15' jeeting' into the step part, the plate extending above the plane of the step.

In testimony whereof I afiix my signature in presence of two witnesses.

JOHN S. TILLEY.

Witnesses ELMER WINTERS, HENRY WINTERS. 

